lateralisation & split brain research L6

• What is hemispheric lateralisation?

  The left hemisphere is dominant for language and speech.
• Why is split-brain research conducted?

  To treat severe epilepsy and prevent seizures.
• What does the right hemisphere specialise in?

  Visuomotor tasks.
• What procedure do surgeons perform to prevent seizures in split-brain patients?

  They cut the nerve fibres of the corpus callosum.
• Who reported that damage to the left hemisphere leads to language deficits?

  Broca in 1861.
• What was the finding of Sperry and Gazaniga (1967) regarding split-brain patients?

  If a picture is shown to the left visual field, it is processed by the right hemisphere.
• Why can't split-brain patients respond verbally to information processed by the right hemisphere?

  Because the right hemisphere has no language centre.
• What connects the two hemispheres of the brain?

  Bundles of nerve fibres such as the corpus callosum.
• What are the advantages of hemispheric lateralisation in cognitive tasks?

  • Engages one hemisphere for a specific task
  • Leaves the other hemisphere free for different functions
  • Enhances brain efficiency in simultaneous tasks
• In chickens, what is brain lateralisation associated with?

  An enhanced ability to perform two tasks simultaneously.
• What did Seaflarski et al. (2006) find about language lateralisation with age?

  Language became more lateralised to the left hemisphere with increasing age in children and adolescents.
• What happens to lateralised patterns as individuals age?

  They tend to switch to bilateral patterns in healthy older adults.
• Why might older adults use the extra processing resources of the other hemisphere?

  To compensate for age-related declines in function.
• What claim of early split-brain research has been disconfirmed by more recent studies?

  That damage to the left hemisphere leads to a loss of language function.
• What did the case study of patient J.W. demonstrate?

  That he developed the capacity to speak about information presented to either hemisphere.
• What does the case of J.W. challenge regarding the right hemisphere?

  It challenges the claim that the right hemisphere is unable to handle even rudimentary language.